During the development of broadband and mobile networks, the 3rd generation partnership Project (3GPP) organization has proposed a Long Term Evolution (LTE) solution for a mobile access network, namely, an evolved universal terrestrial radio access network (E-UTRAN), and a system architecture evolution (SAE) solution for a mobile core network, namely, an evolved packet core network (Evolved Packet Core, EPC).
A single-layer structure formed only by an evolved NodeB (eNB) is used for the E-UTRAN, so as to simplify a network and reduce a delay. An interface between a user equipment (UE) and an eNB is a Uu interface, which is a radio interface connection. A user plane of the Uu interface is mainly used to transfer an internet protocol (IP) data packet, and mainly implements functions, such as header compression, encryption, scheduling, hybrid automatic repeat request (HARQ) and automatic repeat-request (ARQ). A signaling plane of the Uu interface is mainly used to transmit a signaling message. Control-plane signaling of the UE, for example, radio resource control (RRC) signaling, is mapped to a signaling radio bearer (SRB) for transmission; and all IP data packets on the user plane are mapped to different data radio bearers (DRB) for transmission. The SRB and the DRB first undergo packet data convergence protocol (PDCP) sublayer and a radio link control (RLC) sublayer processing, and then are reused at a media access control (MAC) sublayer. The DRB and the SRB of the UE use a same MAC entity, that is, a user plane and a control plane of a same UE are anchored on a same eNB.
In a case in which a macro cell and a pico cell overlap, for a UE with high mobility, if the UE is attached to a macro eNB with a large coverage area, factors affecting user experience, such as service interruption and throughput reduction that may be caused by frequent handovers, may be avoided; however, because the UE needs to be connected to a farther macro eNB, consumption of transmit power and an air interface resource needs to be increased. If the UE is attached to a nearer pico eNB, consumption of an air interface resource may be decreased, but the number of handover times and a handover failure rate are increased, which causes service interruption of the UE.
For the foregoing problems, an idea of separating a control plane and a user plane of an air interface is proposed in the prior art: A signaling base station (signalling BS) provides a control-plane connection of a UE, and a data base station (Data BS) provides a data-plane connection of the UE. In a process of implementing separation of a control plane and a user plane of an air interface, a problem that the data base station dynamically configures, according to a change of a radio channel between the UE and the data base station, a radio resource of an air interface connection between the UE and the data base station of the UE needs to be solved.